Transcript for New Precautions at Airports Over Terror Fears and Hard-to-Detect Bombs

from Washington tonight. The terror fears late today. U.s. Authorities calling for new and sweeping security precautions at airports around the word. There is new concern terrorists are plotting right now. I want to bring in ABC's senior justice correspondent Pierre Thomas opportunity working his sources. These new security sources, what are we talking about, Pierre? Reporter: They're asking some airports overseas to expand their screening of passengers. Look for more random screening, scrutiny of electronics and expanded use of bomb detection machines. Where do authorities believe the planning is taking place and what are they most concerned about? Reporter: This is about fears someone could smuggle a bomb into the U.S. Some of the invideo VA tif bomb makers from Yemen appear to be teaming up with thousands of Al Qaeda fighters in Syria. Many are from western countries and they could have access, easy access to the homeland. Today a 19-year-old woman from the Denver suburbs was arrested for trying to go to Syria. Pierre, thanks. Now to that potentially explosive scene from the south, the showdown near the border. You'll remember the images we

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